The present status of the tobacco industry in the United States has been that because of the decreasing availability of labor and the increasing cost of what labor is available, every effort is being made to use machines and mechanical devices as much as possible in the harvesting and curing of tobacco, and to minimize as much as possible the necessity for manual labor. For instance, thirty years ago nearly all tobacco was cured by tying bunches of leaves on sticks and carefully arranging each of those sticks at spaced apart positions in a curing barn. About ten years ago farmers started using the system of arranging a mass of tobacco leaves in small bulk racks and then loading about 125 of these small racks into a curing barn. The natural evolution of this bulk concept has been to deposit green tobacco leaves in ever larger bulk containers, and now very large containers are filled with green tobacco leaves and the loaded container, weighing 1500-2000 lbs, is hoisted into a barn for curing. It has been found that eighteen such large containers in a curing barn can take the place of one hundred twenty-six of the smaller types of racks that were previously used, thereby eliminating much of the manual manipulation that was heretofore associated with the smaller racks. Large containers are filled by simply dumping leaves in the container in a rather indiscriminate manner and once such containers are filled with a mass of leaves they can be moved into and out of a curing barn by mechanical lifting devices which greatly reduce the manual effort required.
The bulk curing of tobacco is now widely practiced by tobacco farmers. A number of manufacturers offer bulk curing equipment, including bulk curing barns and bulk curing racks. Thus, the combination of components which are already generally known in the art includes:
(a) a bulk curing barn having sides, a floor and a roof, PA1 (b) access means in one side of said barn, said access means being large enough to accommodate the introduction of a box-like tobacco leaf container, said access means being closeable during the bulk curing operation, PA1 (c) a stationary support means located on the interior of said barn, said stationary support means being adapted to support a plurality of containers within said barn in front-to-back relationship, and PA1 (d) means for passing air through the leaves in each container under controlled conditions of time, temperature, humidity and pressure to effect curing of the leaves. PA1 (a) removing tobacco leaves from a tobacco stalk while the plants are in the field, PA1 (b) depositing said removed leaves into a large container that is designed to be placed into a bulk curing barn, PA1 (c) transporting said large container from the tobacco field to a position in the vicinity of a bulk curing barn by means of a vehicle, PA1 (d) generally fixing the position of a majority of the leaves within said container before or after step (c) by forcing a plurality of elongated spike members through the mass of green tobacco leaves within said container and maintaining the position of said spike members substantially stationary with respect to said container during subsequent loading and curing steps, PA1 (e) transferring a plurality of such loaded containers from a position outside the bulk curing barn to a stationary supported position within said bulk curing barn in a side-by-side positional relationship wherein at least the bottom side and top side of each container are provided with sufficient openings to permit the passage of heated gases through the mass of tobacco leaves contained therein, and PA1 (f) moving gas under controlled conditions of temperature humidity and pressure through the mass of leaves in the containers for a sufficient time to cure the leaves. PA1 (1) a main track means adjacent the bottom of said barn, said track means extending from one end of said barn to the other, PA1 (2) a secondary track means forming an extension of said maintrack means and extending outwardly from the interior of said bulk barn through said access means, PA1 (3) a movable container support on said track means and adapted to carry the weight of a loaded container of tobacco leaves, said movable container support having wheels on its underside upon which to move back and forth over at least a substantial portion of the length of said main and secondary track means, PA1 (4) said movable container support including a platform and means to swing said platform from a upper position through a downward arc to a lower position, the upper position of said platform being at a level above said stationary container support means and the lower position of said platform being at a level below said stationary container support means. PA1 (1) transferring each loaded container of green tobacco leaves from a position outside said bulk curing barn to a position inside said bulk curing barn by supporting it upon a vertically adjustable platform that rolls on trackways that extend for substantially the full interior length of the floor of the bulk curing barn and for a substantial distance outside the barn, PA1 (2) adjusting the vertical height of said platform so that as it carries a container full of leaves into the bulk curing barn, the container will not engage the stationary supports in the curing barn that are designed to support the container during the curing operation, PA1 (3) causing said platform to move through a downward and forward arc once said container has arrived at approximately its desired position within the bulk curing barn so that not only is the weight of the container transferred to the stationary support members within the bulk barn but the container is wedged forward tightly against either the back wall of the barn or against the adjacent container, PA1 (4) withdrawing said platform member from said bulk curing barn along said trackway after it has been adjusted downwardly to such an extent that it is no longer supporting said container, PA1 (5) repeating steps (1) through (4) until the bulk curing barn is filled with loaded containers positioned in a close front-to-back relationship, PA1 (6) curing the leaves in the containers, and PA1 (7) subsequent to the curing operation using the vertically adjustable platform in a reverse manner to that set forth in steps (1)-(5) to thus remove all of the containers containing cured tobacco leaves. PA1 (a) a lower frame member PA1 (b) a plurality of wheels mounted at spaced apart points on said lower frame member so as to permit said lower frame member to move back and forth along a track means, PA1 (c) an upper frame member disposed above said lower frame member, PA1 (d) a plurality of linkage members linking said lower frame member to said upper frame member, each of said linkage members having one end pivotally mounted on said lower frame member and the other end pivotally mounted on said upper frame member, and PA1 (e) means for lowering said upper frame member from an upper position with respect to said lower frame member through a downward arc to a lower position with respect to said lower frame member, said means also permitting raising of said upper frame member to its original position.
The combination of method steps which is already generally known in the art include
Some patents which are of interest relative to bulk curing include U.S. Pat. Nos. 3,105,713; 3,110,326; 3,251,620; 3,659,889; 3,088,603 and 3,834,137. The disclosures of these references are incorporated herein by reference for their showings of the apparatus and methods which are already known in the art.
A considerable amount of work on curing in large bulk containers has also been carried out at the North Carolina State University at Raleigh, N.C. by Dr. Charles Suggs. This work is not secret and has been viewed by interested farmers and manufacturers.